Editor’s Note
Cognitive impairment is a syndrome characterized by acquired cognitive function impairment as the core symptom, which can lead to a decline in patients’ daily life and work abilities, with or without accompanying mental and behavioral abnormalities. Depending on its severity, it is divided into subjective cognitive decline (SCD), mild cognitive impairment (MCI), and dementia. Maintaining brain cognitive health is an important part of brain health management. This article will provide a brief explanation of brain cognitive health screening.
Brain Cognitive Health Screening
1. Neuropsychological screening
(1) Overall cognitive function screening
â‘ 8-item Dementia Screening Questionnaire (AD8): The AD8 scoring method is simple and time-saving, commonly used for rapid screening of cognitive impairment and can be self-assessed or assessed by informants.
â‘¡ Mini-Mental State Examination (MMSE): MMSE is one of the most widely used cognitive screening scales. It covers orientation, memory, attention, calculation, language, and visual-spatial abilities. The total score of MMSE is 30 points, with higher scores indicating better cognitive abilities. However, it is greatly influenced by factors such as age, education level, and language, so the cutoff points may vary among different age and education level groups. Its role in identifying MCI is limited.
â‘¢ Montreal Cognitive Assessment (MoCA): MoCA is a comprehensive cognitive function assessment scale designed specifically for screening MCI, covering cognitive areas such as attention, memory, calculation, orientation, language, visual-spatial abilities, executive function, and abstract thinking. It has a total score of 30 points, and higher scores indicate better cognitive abilities. MoCA is superior to MMSE in identifying MCI, mild AD, vascular cognitive impairment, and cognitive impairment caused by Parkinson’s disease. However, in practical applications, low education levels can lead to low scores.
(2) Screening of neuropsychiatric symptoms (NPS)
NPS are early symptoms of dementia and can also be accompanying symptoms that interact with cognitive impairment, making them susceptible to underdiagnosis or misdiagnosis. Screening for NPS can be done using neuropsychiatric questionnaires, Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, self-rating depression scale, self-rating anxiety scale, and Pittsburgh Sleep Quality Index.
(3) Computerized neuropsychological screening tools
Computerized neuropsychological screening tools utilize computers to assist in conducting tests, digitizing the traditional neuropsychological assessment scales, and interpretations, such as digitizing MMSE, MoCA, and Alzheimer’s Disease Assessment Scale-Cognitive part (ADAS-cog).
Additionally, task-based testing systems based on psychological experiment paradigms can be used, such as the Cambridge Neuropsychological Test Automated Battery (CANTAB), BrainCheck, Basic Cognitive Ability Test System (BCAT) developed by the Chinese Academy of Sciences Institute of Psychology, and BABRI Brain Health System developed by Beijing Normal University, among others.
2. Laboratory testing
(1) Blood tests
â‘ Blood tests for cognitive impairment-related indicators: Endocrine metabolism disorders, vitamin deficiencies, infections, toxins, and other factors can lead to cognitive impairment or increase the risk of cognitive impairment. Blood tests provide important reference value for clarifying the etiology and risk factors, typically including complete blood cell count, erythrocyte sedimentation rate, electrolytes, blood glucose, blood lipids, liver and kidney function, thyroid function, vitamin B12, folic acid, homocysteine, etc. When necessary, additional relevant tests for syphilis, HIV, heavy metals, drugs, or toxins may also be considered based on personal history.
② AD-related blood biomarkers: Blood biomarkers such as amyloid beta 42 (Aβ42), amyloid beta 40 (Aβ40), phosphorylated tau protein (P-tau181), and neurofilament light chain levels show good correlations with cerebrospinal fluid and positron emission tomography (PET) results. In addition, levels of P-tau217 and P-tau231 are associated with cognitive decline and may elevate even in the preclinical stage of AD. However, the detection technology and clinical application of AD-related blood biomarkers still require further research and optimization.
③ Genetic testing: Genetic factors, including susceptibility genes and pathogenic genes, in combination with environmental factors, increase the risk of cognitive impairment. The apolipoprotein E (ApoE) ε4 allele gene is associated with late-onset sporadic AD and may lead to early-onset AD. Common AD pathogenic genes include presenilin (PSEN) 1, PSEN2, and amyloid precursor protein (APP) genes, with mutation carriers having a 100%, 95%, and 100% probability of developing AD, respectively, typically before the age of 65.
(2) Urine tests
High levels of urine AD7C neurofilament protein (AD7C-NTP) are associated with cognitive decline. However, its clinical application requires further evidence from large-scale cohort studies.
(3) Cerebrospinal fluid (CSF) tests
CSF tests help differentiate the etiology of cognitive impairment. CSF biomarkers such as Aβ42, P-tau, T-tau are highly correlated with AD. However, lumbar puncture is an invasive procedure and is not recommended for routine brain cognitive health screening.
3. Imaging screening
(1) Structural brain magnetic resonance imaging (sMRI)
Studies on dementia genetics have shown changes in sMRI years before clinical symptoms appear. In addition, other MRI scan techniques like diffusion tensor imaging and functional magnetic resonance imaging (fMRI), combined with artificial intelligence analysis such as machine learning, can effectively predict and diagnose cognitive impairment early.
(2) Head CT
Head CT scans can detect tumors, hematomas, cerebral infarctions, brain atrophy, ventricular enlargement, and hydrocephalus, but compared to head MRI, they are less accurate in displaying fine brain structures like the olfactory cortex and hippocampus.
(3) PET
Fluorodeoxyglucose (FDG)-PET, Aβ-PET, and Tau-PET reflect brain metabolism levels, abnormal deposition of Aβ and Tau proteins, aiding in early diagnosis of AD and screening for the etiology of cognitive impairment.
4. Electrophysiological tests
Using binaural integration paradigms combined with evoked potential measurements can assess the degree of central auditory impairment in subjects, showing promising potential for early screening of cognitive impairment in AD. The area under the receiver operating characteristic curve is 0.92–0.94 for distinguishing early dementia in AD and 0.88–0.90 in MCI stages.
5. Behavioral biomarkers screening
Gait speed may serve as a simple non-invasive early biomarker for recognizing cognitive decline, especially dual-task (simultaneously performing motor and cognitive tasks) gait testing being more sensitive to cognitive decline. Additionally, early behavioral changes such as hearing loss, visual impairment, olfactory dysfunction, and eye movement abnormalities can assist in early identification and progression prediction of cognitive impairment.
Screening of Brain Cognitive Health-Related Risk Factors
1. Screening for modifiable risk factors
Recommended cognitive impairment-related modifiable risk factors screening for appropriate populations includes education level, hearing loss, traumatic brain injury, hypertension, diabetes, abnormal blood lipids, overweight or obesity, cardiovascular diseases, smoking, heavy alcohol consumption, depression, lack of social activities, and physical inactivity.
2. Screening for non-modifiable risk factors
Non-modifiable risk factors such as age, gender, genetic factors, and family history are also associated with brain cognitive health. Advanced age, female gender, family history of dementia, carrying the risk gene ApoEε4, and mutations in pathogenic genes (APP, PSEN1, and PSEN2 genes) all contribute to varying degrees of increased risk for cognitive impairment.
References
[1] Loy CT, Schofield PR, Turner AM, et al. Genetics of dementia. Lancet. 2014;383(9919):828-840. DOI: 10.1016/S0140-6736(13)60630-3.
[2] Brain Cognitive Health Management China Expert Consensus Formulation Committee, Editorial Committee of Chinese Journal of Health Management. China Expert Consensus on Brain Cognitive Health Management (2023). Chinese Journal of Health Management. 2023;17(12):881-892. DOI: 10.3760/cma.j.cn115624-20230908-00124.
[3] Teipel S, Drzezga A, Grothe MJ, et al. Multimodal imaging in Alzheimer’s disease: validity and usefulness for early detection. Lancet Neurol. 2015;14(10):1037-1053. DOI: 10.1016/S1474-4422(15)00093-9.
Source: Internal Neurology Circle
Disclaimer: This content is intended for healthcare professionals only
